A main shaft is a key component of a wind turbine, which connects a rotator with a gearbox for passing energy. However, complex force and wear inevitably lead to cracks and other defects in the main shaft during a long operation process. For the normal operation of the main shaft and wind turbine, it is important to find the defects.
However, the wind turbine is far away from the ground, typically, the wind turbine is established on an ocean platform, which is far away from the land (few kilometers to tens of kilometers), thus it is difficult to detect the defects in the main shaft of the wind turbine in real time.
In the related art, in order to detect the defects in a main shaft of the wind turbine, it is necessary to shut down the wind turbine and the inspector needs to enter into a wind turbine monitor room to detect the main shaft, which may lead to financial loss, and a waste of manpower, material and financial resources.
Moreover, during the operation process of the wind turbine, the main shaft rotates in circumferential direction, and the rotate speed varies continually. If the main shaft is detected after the wind turbine is shut down, it is difficult to monitor the operation conditions of the main shaft, such that it is inconvenient to know the actual condition of the main shaft.